Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income	$ 229,484	$ 237,951	$ 183,684
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	45,100	52,279	33,684
Provision (benefit) for deferred income taxes	47,269	44,666	(17,819)
Depreciation and amortization	63,919	53,802	38,236
Benefit attributable to FDIC loss share	6,373	2,920	10,790
Accretion of acquired loans	(92,995)	(136,776)	(154,487)
Amortization and accretion of investment securities, net
Available for sale	9,393	11,734	17,274
Held to maturity	4,828	4,800	7,609
Losses (gains) on sales and calls of available-for-sale investment securities, net	(957)	(166)	2,803
Originations of loans held for sale	(68,747)	(358,301)	(550,193)
Proceeds from sales of loans, primarily mortgage loans sold in the secondary markets	77,913	363,732	574,321
Gains on sales of loans, net	(1,210)	(7,237)	(12,067)
Amortization of intangible assets	10,392	11,735	8,392
Recognition of stock compensation expense	15,020	13,922	10,937
Net decrease (increase) in other assets	11,751	(26,707)	181,772
Net increase (decrease) in other liabilities	(43,833)	16,283	(25,570)
NET CASH PROVIDED BY OPERATING ACTIVITIES	313,700	284,637	309,366
Proceeds from sale of securities
Available-for-sale	370,946	22,463	2,179,728
Held-to-maturity	668	32,486	89,554
Other	1,413	7,088	897
Proceeds from prepayments, calls, and maturities
Available-for-sale	584,833	486,100	699,647
Held-to-maturity	438,882	390,882	245,259
Other	165	0	0
Purchases of securities
Available-for-sale	(1,371,644)	(754,518)	(1,059,130)
Held-to-maturity	(214,062)	(378,678)	(1,832,993)
Other	(402)	(388)	(3,098)
Net decrease (increase) in loans and leases	(719,311)	(952,518)	171,929
Purchases of premises and equipment	(37,358)	(69,346)	(40,632)
Sales of premises and equipment	9,472	26,509	1,110
Cash received for acquisition, net of cash paid	0	0	188,948
NET CASH PROVIDED (USED) BY INVESTING ACTIVITIES	(936,398)	(1,189,920)	641,219
Financing Activities
Net increase in demand accounts	603,427	329,786	835,011
Net increase (decrease) in savings and money market accounts	50,511	(187,555)	176,513
Net (decrease) in certificates and other time deposits	(50,600)	(171,167)	(514,103)
Net increase (decrease) in securities sold under agreements to repurchase	(235,516)	421,056	(367,995)
Increase (decrease) in long-term debt	0	180,764	249,930
Net increase (decrease) in wholesale borrowings	152,577	227,471	(655,603)
Repurchase of common stock warrant	12,150	0	0
Net proceeds from issuance of preferred stock	0	0	96,550
Cash dividends - common	(108,887)	(105,333)	(96,222)
Cash dividends - preferred	(5,876)	(5,876)	(5,337)
Restricted stock activity	(4,395)	(4,261)	(9,521)
NET CASH PROVIDED (USED) BY FINANCING ACTIVITIES	389,091	684,885	(290,777)
Increase (decrease) in cash and cash equivalents	(233,607)	(220,398)	659,808
Cash and cash equivalents at beginning of year	697,424	917,822	258,014
Cash and cash equivalents at end of year	463,817	697,424	917,822
SUPPLEMENTAL DISCLOSURE OF CASH FLOWS INFORMATION:
Non-cash transaction: Common Stock issued in merger with Citizens	0	0	925,211
Non-cash transaction: Consideration from the warrant issued to the Treasury for Citizens TARP	0	0	3,000
Cash paid during the year for:
Interest expense	57,284	55,424	50,055
Federal income taxes	$ 46,825	$ 35,981	$ 27,662